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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14
// <optional>
// From LWG2451:
// template <class U>
// optional<T>& operator=(optional<U>&& rhs);
#include <optional>
#include <array>
#include <cassert>
#include <memory>
#include <type_traits>
#include "test_macros.h"
#include "archetypes.h"
using std::optional;
struct X
{
static bool throw_now;
X() = default;
X(int &&)
{
if (throw_now)
TEST_THROW(6);
}
};
bool X::throw_now = false;
struct Y1
{
Y1() = default;
Y1(const int&) {}
Y1& operator=(const Y1&) = delete;
};
struct Y2
{
Y2() = default;
Y2(const int&) = delete;
Y2& operator=(const int&) { return *this; }
};
struct B { virtual ~B() = default; };
class D : public B {};
template <class T>
struct AssignableFrom {
static int type_constructed;
static int type_assigned;
static int int_constructed;
static int int_assigned;
static void reset() {
type_constructed = int_constructed = 0;
type_assigned = int_assigned = 0;
}
AssignableFrom() = default;
explicit AssignableFrom(T) { ++type_constructed; }
AssignableFrom& operator=(T) { ++type_assigned; return *this; }
AssignableFrom(int) { ++int_constructed; }
AssignableFrom& operator=(int) { ++int_assigned; return *this; }
private:
AssignableFrom(AssignableFrom const&) = delete;
AssignableFrom& operator=(AssignableFrom const&) = delete;
};
template <class T> int AssignableFrom<T>::type_constructed = 0;
template <class T> int AssignableFrom<T>::type_assigned = 0;
template <class T> int AssignableFrom<T>::int_constructed = 0;
template <class T> int AssignableFrom<T>::int_assigned = 0;
void test_with_test_type() {
using T = TestTypes::TestType;
T::reset();
{ // non-empty to empty
T::reset_constructors();
optional<T> opt;
optional<int> other(42);
opt = std::move(other);
assert(T::alive == 1);
assert(T::constructed == 1);
assert(T::value_constructed == 1);
assert(T::assigned == 0);
assert(T::destroyed == 0);
assert(static_cast<bool>(other) == true);
assert(*other == 42);
assert(static_cast<bool>(opt) == true);
assert(*opt == T(42));
}
assert(T::alive == 0);
{ // non-empty to non-empty
optional<T> opt(101);
optional<int> other(42);
T::reset_constructors();
opt = std::move(other);
assert(T::alive == 1);
assert(T::constructed == 0);
assert(T::assigned == 1);
assert(T::value_assigned == 1);
assert(T::destroyed == 0);
assert(static_cast<bool>(other) == true);
assert(*other == 42);
assert(static_cast<bool>(opt) == true);
assert(*opt == T(42));
}
assert(T::alive == 0);
{ // empty to non-empty
optional<T> opt(101);
optional<int> other;
T::reset_constructors();
opt = std::move(other);
assert(T::alive == 0);
assert(T::constructed == 0);
assert(T::assigned == 0);
assert(T::destroyed == 1);
assert(static_cast<bool>(other) == false);
assert(static_cast<bool>(opt) == false);
}
assert(T::alive == 0);
{ // empty to empty
optional<T> opt;
optional<int> other;
T::reset_constructors();
opt = std::move(other);
assert(T::alive == 0);
assert(T::constructed == 0);
assert(T::assigned == 0);
assert(T::destroyed == 0);
assert(static_cast<bool>(other) == false);
assert(static_cast<bool>(opt) == false);
}
assert(T::alive == 0);
}
void test_ambiguous_assign() {
using OptInt = std::optional<int>;
{
using T = AssignableFrom<OptInt&&>;
T::reset();
{
OptInt a(42);
std::optional<T> t;
t = std::move(a);
assert(T::type_constructed == 1);
assert(T::type_assigned == 0);
assert(T::int_constructed == 0);
assert(T::int_assigned == 0);
}
{
using Opt = std::optional<T>;
static_assert(!std::is_assignable<Opt&, const OptInt&&>::value, "");
static_assert(!std::is_assignable<Opt&, const OptInt&>::value, "");
static_assert(!std::is_assignable<Opt&, OptInt&>::value, "");
}
}
{
using T = AssignableFrom<OptInt const&&>;
T::reset();
{
const OptInt a(42);
std::optional<T> t;
t = std::move(a);
assert(T::type_constructed == 1);
assert(T::type_assigned == 0);
assert(T::int_constructed == 0);
assert(T::int_assigned == 0);
}
T::reset();
{
OptInt a(42);
std::optional<T> t;
t = std::move(a);
assert(T::type_constructed == 1);
assert(T::type_assigned == 0);
assert(T::int_constructed == 0);
assert(T::int_assigned == 0);
}
{
using Opt = std::optional<T>;
static_assert(std::is_assignable<Opt&, OptInt&&>::value, "");
static_assert(!std::is_assignable<Opt&, const OptInt&>::value, "");
static_assert(!std::is_assignable<Opt&, OptInt&>::value, "");
}
}
}
TEST_CONSTEXPR_CXX20 bool test()
{
{
optional<int> opt;
optional<short> opt2;
opt = std::move(opt2);
assert(static_cast<bool>(opt2) == false);
assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
}
{
optional<int> opt;
optional<short> opt2(short{2});
opt = std::move(opt2);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
assert(*opt == *opt2);
}
{
optional<int> opt(3);
optional<short> opt2;
opt = std::move(opt2);
assert(static_cast<bool>(opt2) == false);
assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
}
{
optional<int> opt(3);
optional<short> opt2(short{2});
opt = std::move(opt2);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
assert(*opt == *opt2);
}
enum class state_t { inactive, constructed, copy_assigned, move_assigned };
class StateTracker {
public:
constexpr StateTracker(state_t& s)
: state_(&s)
{
*state_ = state_t::constructed;
}
StateTracker(StateTracker&&) = default;
StateTracker(StateTracker const&) = default;
constexpr StateTracker& operator=(StateTracker&& other) noexcept
{
*state_ = state_t::inactive;
state_ = other.state_;
*state_ = state_t::move_assigned;
other.state_ = nullptr;
return *this;
}
constexpr StateTracker& operator=(StateTracker const& other) noexcept
{
*state_ = state_t::inactive;
state_ = other.state_;
*state_ = state_t::copy_assigned;
return *this;
}
private:
state_t* state_;
};
{
auto state = std::array{state_t::inactive, state_t::inactive};
auto opt1 = std::optional<StateTracker>(state[0]);
assert(state[0] == state_t::constructed);
auto opt2 = std::optional<StateTracker>(state[1]);
assert(state[1] == state_t::constructed);
opt1 = std::move(opt2);
assert(state[0] == state_t::inactive);
assert(state[1] == state_t::move_assigned);
}
{
auto state = std::array{state_t::inactive, state_t::inactive};
auto opt1 = std::optional<StateTracker>(state[0]);
assert(state[0] == state_t::constructed);
auto opt2 = std::optional<StateTracker>(state[1]);
assert(state[1] == state_t::constructed);
opt1 = opt2;
assert(state[0] == state_t::inactive);
assert(state[1] == state_t::copy_assigned);
}
return true;
}
int main(int, char**)
{
#if TEST_STD_VER > 17
static_assert(test());
#endif
test_with_test_type();
test_ambiguous_assign();
test();
{
optional<std::unique_ptr<B>> opt;
optional<std::unique_ptr<D>> other(new D());
opt = std::move(other);
assert(static_cast<bool>(opt) == true);
assert(static_cast<bool>(other) == true);
assert(opt->get() != nullptr);
assert(other->get() == nullptr);
}
#ifndef TEST_HAS_NO_EXCEPTIONS
{
optional<X> opt;
optional<int> opt2(42);
assert(static_cast<bool>(opt2) == true);
try
{
X::throw_now = true;
opt = std::move(opt2);
assert(false);
}
catch (int i)
{
assert(i == 6);
assert(static_cast<bool>(opt) == false);
}
}
#endif
return 0;
}
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